Industrial truck



March 20, 1945. H. F. WILMS INDUSTRIAL TRUCK Filed Aug. 25, 1943 6 Sheets-Sheet 1 IIVVVENTOR. HENRY, F. WILMS. p

March 20, 1945. F, WILMS INDUSTRIAL mucx e Sheets-Sheet 3 Filed Aug. 25, 1943' INVENTOR. HENRY WILMS.

6 Sheets-Sheet 4 INVENTOR. I HENRY r. WILMS.

H.- F. WlLMS INDUSTRIAL TRUCK Filed Aug. 25, 1945 March 20, 1945.

H. F. WILMS INDUSTRIAL TRUCK Filed Aug.'25, 1945 e Sheets- Sheet a mmvrox ENRY F. WPILMS; B wwwz dling of heavy loads,

Patented Mee'zo, 1945 a v UNITED s ATEsP- EN Y I l I l2,371,66 1

. TRUCK t Henry F. Wilms, Cleveland, Ohio, assignor to The Elwell-Parker Electric Company, Ohio, a corporation of .Ohio

Qleveland d i ApplicationAugust 25, 1943; sea No 499,942: f 1. 1- a a a .7 jzzcl aims This invention relates, asf-indicated, to industrial trucks, but has reference "more particularly to a' truck of this characterwhich has been designed particularly for use in handling stacked cartons of merchandise and sacks of bulk'mate riaLsuch as flour, potatoes, and the like. 7 1

Industrial lift trucks haveheretofore been de'isigned in which a load carrying skid is retained on the prongs or forks of a vertically 'reciproca ble elevating mechanism, while the load is being unloaded or pushed from the pallet by meansoff v a pusher plate or like structure.

Such trucks have not proved entirely'satisfacf.

tory, due to the fact that in all cases the pusher structure is operated hydraulically, necessitating? carrying on the trucksuitable means for such;

hydraulic operation, inaddition to theusual bat tery for the operation'of the truck; 7 h a Another drawback tothe use of such truck-Sis the fact that" the power developed. throiighfhydraulic operation of the'pusher structurejforthe purpose of moving the pusher structure in relal tion to the truck or the truck in relation to" the pusher structure has not always proved to' be' sufficient nor adequate, particularly in the Han Other shortcomings failure to provide means for preventing a oer;

tain amount of friction between the load and the pusher in the last stages of unloading, which frequentlyresults in some damage to the bottom 3 units of. the load, the failure to providelsatisfac tory. means for latching the prongs or forks of the elevator to the pallet, and the failure to pro-j vide a centralized control to facilitate the ma nipulation of the truck relative to the load trans;

ferring action of the load handling meansand a lack of adequate means for automatically cutting oil and onthe power required to move the pusher a structure. i

The present invention has as its primary ob: ject the provision of v an industrial truck of the character described in which all or substantially all ofthe aforesaid disadvantages andclefects in construction and operation have been obviated, More specifically, the truck of the present in -L vention has incorporated therein numerous high- 1y. advantageous features among which the fol lowing maybe enumerated.

1 1). A pusher or pusherstructure of and well balanced construction; p t

(2) "Mechanism for operating the pusher, which is located as close to the pusher as possi a rugged bleand adequate for the handlingof very heavy loads @Fig. 3 is a rear elevational view of tor and pushenstr'ucture; as viewed in thedirec-i tion indicated bythe line 3-""3 'of Fig. 1; l p

or uc ru re the! f ed parts; i 1 i Figt=a12 is a view; showing in a more or lessrdia- (3) A unique. andhighly satisfactory latching mechanism for retainingthe'pallet on the prongs; or forks of the elevator; j C .1 i (4) Means for eliminating frict'ion between the.

operation; a

; pusher and the load during the "entire-unloading;

eroperation off at predetermined limitsp'and (6) Means for permitting .self adjustment of thepusher when engagingla load at :anrangle; z": t a

Other objects'and advantages of the invention willbe apparent during the course offthe follow:

ing description. M

In the accompanying drawingaforming a part of this specification, and inwhich like numerals are employed to'designate' like parts throughout} rthesamef, w H l *Fig. 1' is a fragmentary side elevation of anindustrial truck embodying the novel featuresjof thepresentinvention;v

f Fig. 2 is acrosssectional view taken approxiniately on the line2 -2 of Fig. 1: I 5

' "Figxtia'is a fragrhentarydetailj showingthe" manner in which the-elevator is guided in'itsver ti'cal movements; a L] Fig. 4 is a'rear'elevation of thepusher screenf Fig. 5 isa side elevation of thepusher screeh;

Fig.6 is a fragmentary]cross sectionalPview; showing the manner in which the elevator guid ing wheels are mounted on the elevator t me" Fig. '7 is a view; palrtlydnhross-sectibn and partly in elevation; showing the rightside ofthe elevator and pusher structure;

Fig. sisla' cross-sectional view, takenon [Fig.2 is a .view similar to Fig.3? 'butof th e left side of the elevator and pusher structure Fig. ,10 is acrossesectional view,taken onthe line Ill-l0 of Fig. 9;

11 is aTfragmentary .view, showing the latching mechanism for the v pallet, and associatrammatic manner, the position of 1 the various parts of the truckfjustxprior: to unloading the Fi 13 is a view similar tong; 12 but'showing the last stages of ithe unloading operation,

andf. 4 a a a a Fig. 14 isa view, showing amodified formof the invention, in which provision is made for 1 (5) Meansfor automatically cutting the push-- the eleva The frame 4' comprises spaced channels (see,

Fig. 311.) having filler strips 6, which serve as tracks or guides for the wheels I of a vertically reciprocable elevator, generally designated The elevator is propelled up or down along the frame 4 by means of cable or chains 8 (Fig. 1),.

the ends of which are attached in any suitable manner to the elevator E, such chains or cables being driven by a motor 9, which derives its motive power from the battery I.

. The elevator E, as best shown in Figs. 2 and 3, includes a frame consisting of a body plate ill, a top plate H, a bottom plate 12, side plates l3 and I4, and a pair of intermediate plates l5,which extend rearwardly from the plate Ill and are disposed in planes parallel with the side plates 13 and i4. Extending between the intermediate plates |5.ls a shelter bracket l6 which servesto support a motor 11. Extendingbetween the intermediate plates l5 and the side plates l3 and I4 are plates l8having a plurality of longitudinally spaced openings I9 therein, which serve a' purpose to be presently described The intermediate plates l5 have welded thereto stub. shafts 28 (Fig. 6) upon which roller bearings 2| are mounted for the frictionless support of the wheels I, which, as previously stated, are guided. by'the channels 5 of .the frame4 during theupward 0 downward movement of the elevator.

The elevator frame is provided with a pair of transversely extending shafts 22 (see Figs. 3,' 8 and 10) which serve as supports for a pair of laterally spaced forks 23, which are restrained against lateral movement by means of dogs 24 which extend through the apertures IS in the plates l8 of the elevator frame andinto recesses nalled in roller bearings which are supported by the plate In of the elevator frame.

The shafts 44 have rigidly secured to their inboard ends gears 46 (Fig. 2) which are driven by pinions 41, which, in turn, are driven by a worm wheel 48, driven by a worm (not shown), but which is driven by the shaft of the motor [1. The worm and worm wheel are encased in a suitable housing. 1

' The shafts 44 have keyed thereto, at points intermediate the bearings 42 and 43, pinions 50, ro-

tation of which imparts reciprocatory movement The racks 5| extend through the tubular portions 29 and 34 of the rack cases 28 and "33 and have secured to the rear ends thereof collars 52, whereby the racks maybe slid along the inner walls of tubular housings 53, which are are in retracted-position, but to prevent access of dirt and dust thereto.

. Secured to the forward ends of the racks 5| are latch trips comprising hub portions and portions 56 of T-shaped cross-section, extending from the upper. .and lower faces of said hub portions.

, or screen 58. The pusher 58 consists of a somein the upper ends of the forks. By providing 3 a plurality of recesses IS in the plates 18, adjust-. ment ofthe forks along the shafts 22 may be made whengdesired. The function of the forks 23 will'be presentlydescribed.

Secured to the plate l3, as by means of 25 and nuts 26, is a split flangev 21, which serves to secure to the plate l3 a rack case 28 of generally cylindrical form and having a tubular portion 29 extending rearwardly and tangentially bolts therefrom (Fig. 9). Similarly, the plate has secured thereto, as by means of bolts 38 and nuts 3|, asplit flange 32, which serves to secure to the plate I4 a rack case 33 of generally cylindrical form and having a tubular portion 34 extending .rearwardly and tangentially therefrom (Fig. 7)..

In order to more effectively support the rack cases 28 and 33-on the frame, each of the rack cases is rovided at its inboard end with'a tubular extension 35 which. extendsinto and substan what rectangular frame 59, a vertical frame member 60 anda multiplicityv 0f vertically-spaced, transversely extending frame bars 6|. The piv- ,otal connection of the pusher 58 to the latch trip hubs 55 permits a limited tilting movement of the pusher relatively to the racks for a purpose. to be presently described. I

-The forks 23 are so designed as to be insertable into the usual load-carrying skid or pallet for the support and transportation of which trucks of the character described are designed. Such skids or pallets are usually constructed inthe manner shown in Figs. 11, 12 and 13 and consist'of an upper board B, a lower board L, sides S, and a central longitudinally extending vertically disposed partition P, all of these parts usually formed of wood or like material. For the purposes of the present invention, the upper board B will be covered with a mooth sheet of metal or other material upon which a load may be slid, and the central partition P will be provided at opposite sides of the rear portion thereof, with metallic plates P to which a plurality of longitudinally spaced angles A are secured. Each of the forks 23 is also provided with a triangular shaped cleat 62 on its inboard side ata point adjacent the rear of the fork, each of such cleats having a sloped side 63.

Mechanism is also provided for retaining the pallet which has been described on the forks 23 while a load is being pushed off the pallet by the pusher 58. Such mechanism includes a pair of latch bars E4having hook-shaped forward ends 65, the latch bars bein pivotally connected as at 66, to the bottom plate l2 of the elevator frame. The latch bars are normally maintained in the position shown in solid lines in Fig. 11, due to theengagement of the lower portions 56 of the' latch trips with screws 16. A coil spring 6'! is secured at one end to an eyebolt 68 which is adjustably secured to a bracket 69 which, in turn. is secured to a link 10. The other end. of the i spring 6'! is secured to one arm H of a bell-crank lever, which iskeyed to the lower end of a vertithe dotted lines. The-extent of this rotation in either direction is limited by the provision of stops 98,"and springs 99 are. interposed'between the pusher screen 58 and the cross-bar 96 to cushion the impact resulting fromengagement of the pusher with the load, as well as .to restore the pusher to'its normal position, which is parallel- With the bar 96.

It is thus seen that we have provided a truck having incorporated therein all of the desirable features which have hereinbefore been enumer-" ated. a

It'will be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and 'arstructure and .rack and gear means for moving said pusher structure relatively tolsaid elevator structure, said racks being tiltable in vertical planes relatively to said elevator structure.

3. In a truck of the character described, a verticallyreciprocable elevator structure, a pusher structure, and. means comprising an electric motor, racks and gears carried directly by said elevator structure for moving said pusher structurerelatively to said elevator structure.

4. In a truck of the character described, an elevator structure, a pusher structure, and means for moving said pusher structure relatively to said elevator structure, said means including an electric motor, racks and gears mounted directly on said elevator structure. e v

5. In a truck of the character described, an elevator structure, a pusher structure disposed in advance of said elevator structure, and means for moving said pusher structure relatively to said elevator structure, said means including a motor mounted on said elevator structure, a pair of shafts journalled on said elevator structure and driven by said motor, pinions driven by said shafts, and racks mounted on said elevator structure and driven by said pinions, said racks being connected at one end to said pusher structure.

6. In a truck of the character described, an elevator structure, ajpusher structure disposed in advance of said elevator structure, and means for -moving said pusher structure relatively to said elevator structure, said means including a motor mounted on said elevator structure, a pair of shafts journalled .on said elevator structure and driven by said "motor, .pinionsdriven by said,

shafts, and racks mounted on said elevator structure and driven by said pinions, said racks being tiltable about the axes of said pinions. t 7. In a truck of the character described, an elevator structure, rack cases pivotally mounted on said elevator structure, pinions wholly en closed Within said cases, and racks extending through said cases and adapted to be driven by said pinions.

8. In a truck of the character described, an elevator frame, and rack cases mounted on the rangement of parts may be resorted to, without sides of said frame and rotatable injthe plane of said sides.

9. .In'atruck of the character described, an elevatorframe, rack cases mounted on the sides of saidframe and rotatable in the plane of said sides, andtubular rackhousings secured to said cases and extending along the sides of said truck.

10. In atruck of the character described, anelevator structure, a pusher structure movable between predetermined limits, means including a motor mounted on said elevator structure for moving said pusher structure relatively to said elevator structure, and means responsive to the movement of said pusher structure to said limits for deenergizing said motor. f

11. In a truck of the character described, an elevator structure; a pusher structure movable between extreme positions relatively to said elevator structure, power means for efiecting said movement, and means responsive to the movement of said pusher structure to said extreme positions for deenergizing said power means.

12. In a truck of the character described, a pusher structure movable between predetermined positions; power means for eifecting said movement, limit switches for deenergizing said power means, and means responsive to movement of the pusher structure to said positions for actuating said switches.

13. In a truck of the character described, an elevator'st-ructure adapted for the support of a pallet, means for pushing a load from said pallet,

' latch bars pivotally mounted on said elevator structure and adapted to retain saidpallet on said structure during removal of said load from the pallet, and means responsive to movement of said load pushing means for releasing said latch bars from saidpallet. 3

14. In a truck of the character described, an elevator structure having forks'mounted thereon, and cleats having sloping sides mounted on the sides of said forks, said cleats adapted for properly aligning said forks with a skid which is to be picked up by means of said forks.

'15. In a truck of the character described, an elevator frame, rack'cases mounted on the sides of said frame, said cases having tubular extensions, and means secured to the sides of said frame for supporting said tubular extensions.

16. In a truck of the character described, an elevator, a pusher structure, and means for moving said pusher structure relatively tosaid elevator structure, said means comprising racks pivotally movable relatively to said elevator structure. I

s 17. In a truckof the character described, a vertically reciprocable elevator, a pusher, means for moving said pusher structure relatively to said elevator, and means permitting vertical downwardmovementof said pusher relatively to said elevator when said pusher is substantially at its farthest position from said elevator.

18. In atruckofthe characterjdescribed, a

vertically-rciprocable elevator having a substantially-horizontal load supportingportion, a pusher, means for moving said pusher relatively to said elevator and substantially parallel to said horizontal portion to remove loads supported by the latter, and means permitting vertical downward movement of said pusher at substantially the ex'tremelimit of its movement from said ele-- vator whereby the pusher remains in engagement withtheload asthe load descends.

' 19. Ina truck of the character described, an elevator frame, rack. casesmounted on the sides of said frame and rotatable in the plane of said sides from a position substantially perpendicu tain said pallet on said structure during removal of said load from the pallet, means maintaining said latch bars in inoperative position at such time when said pushingmeans is substantially in completely retracted position, and means responsive to movement of said pushing means from said retracted position for moving said latch bars to the pallet retaining position.

21. In a truck of the'character described, a vertically-reciprocable elevator structure, and a pusher structure movablerelatively to said elevator structure, said pusher structure comprising a load-engaging element mounted for limited pivotal movement about a vertical axis;

22. A truck as defined in claim 21, and means resiliently cushioning the pivotal movement of said load-engaging element.

. HENRY F. WILMS. 

